4.4BSD/usr/share/man/cat2/pathconf.0

PATHCONF(2)                 BSD Programmer's Manual                PATHCONF(2)

NNAAMMEE
     ppaatthhccoonnff, ffppaatthhccoonnff - get configurable pathname variables

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<uunniissttdd..hh>>

     _l_o_n_g
     ppaatthhccoonnff(_c_o_n_s_t _c_h_a_r _*_p_a_t_h, _i_n_t _n_a_m_e);

     _l_o_n_g
     ffppaatthhccoonnff(_i_n_t _f_d, _i_n_t _n_a_m_e);

DDEESSCCRRIIPPTTIIOONN
     The ppaatthhccoonnff() and ffppaatthhccoonnff() functions provides a method for applica-
     tions to determine the current value of a configurable system limit or
     option variable associated with a pathname or file descriptor.

     For ppaatthhccoonnff, the _p_a_t_h argument is the name of a file or directory.  For
     ffppaatthhccoonnff, the _f_d argument is an open file descriptor.  The _n_a_m_e argument
     specifies the system variable to be queried.  Symbolic constants for each
     name value are found in the include file <unistd.h>.

     The available values are as follows:

     _PC_LINK_MAX
             The maximum file link count.

     _PC_MAX_CANON
             The maximum number of bytes in terminal canonical input line.

     _PC_MAX_INPUT
             The minimum maximum number of bytes for which space is available
             in a terminal input queue.

     _PC_NAME_MAX
             The maximum number of bytes in a file name.

     _PC_PATH_MAX
             The maximum number of bytes in a pathname.

     _PC_PIPE_BUF
             The maximum number of bytes which will be written atomically to a
             pipe.

     _PC_CHOWN_RESTRICTED
             Return 1 if appropriate privileges are required for the chown(2)
             system call, otherwise 0.

     _PC_NO_TRUNC
             Return 1 if file names longer than KERN_NAME_MAX are truncated.

     _PC_VDISABLE
             Returns the terminal character disabling value.

RREETTUURRNN VVAALLUUEESS
     If the call to ppaatthhccoonnff or ffppaatthhccoonnff is not successful, -1 is returned
     and _e_r_r_n_o is set appropriately.  Otherwise, if the variable is associated
     with functionality that does not have a limit in the system, -1 is re-
     turned and _e_r_r_n_o is not modified.  Otherwise, the current variable value
     is returned.

EERRRROORRSS
     If any of the following conditions occur, the ppaatthhccoonnff and ffppaatthhccoonnff

     functions shall return -1 and set _e_r_r_n_o to the corresponding value.

     [EINVAL]      The value of the _n_a_m_e argument is invalid.

     [EINVAL]      The implementation does not support an association of the
                   variable name with the associated file.
     PPaatthhccoonnff() will fail if:

     [ENOTDIR]       A component of the path prefix is not a directory.

     [ENAMETOOLONG]  A component of a pathname exceeded 255 characters, or an
                     entire path name exceeded 1023 characters.

     [ENOENT]        The named file does not exist.

     [EACCES]        Search permission is denied for a component of the path
                     prefix.

     [ELOOP]         Too many symbolic links were encountered in translating
                     the pathname.

     [EIO]           An I/O error occurred while reading from or writing to
                     the file system.

     FFppaatthhccoonnff() will fail if:

     [EBADF]   _f_d is not a valid open file descriptor.

     [EIO]     An I/O error occurred while reading from or writing to the file
               system.

SSEEEE AALLSSOO
     sysctl(3)

HHIISSTTOORRYY
     The ppaatthhccoonnff and ffppaatthhccoonnff functions first appeared in 4.4BSD.

4th Berkeley Distribution        June 4, 1993                                2